Motor vehicle spring suspension



Aug. 19, 1952 w. D. ALLlsoN MOTOR VEHICLE SPRING SUSPENSION original Filed April 12, 1944 4 Sheets-Sheet l www P w.

n n! uw m W INVENToR M/ZZZz'd/z HZZzso/z ATTORNEYS.

Aug. 19, 1952 l w. D. ALLlsoN .2,607,611

MOTOR VEHICLE SEEING SUSPENSION Original Filed April 12, 1944l 4 sheets-sheet 2 INVENTOR ATTORNELS Allg- 19, 1952 w. D. A| |soN 2,607,611

MOTOR VEHICLE SPRING SU'SPENSION Original Filed April l2, 1944 4 Sheets-Sheet 5 Aug. 19, 1952 w. D. ALLlsoN MOTOR VEHICLE SPRING SUSPENSION 4 Sheets-Sheet 4 Original Filed April l2, 1944 INVENTOR William Z HZZZ'Sf?.

A TTORN E K5.

Patented Aug. 19, 1952 Continu-ationfof aprilvicafion ,SeriaLNo. 530,661, Apriln 12,-, 19441. d This application J une 27, 1947l I9' Claims: (01,281)*-100 Whelat' the s agnge:side ofl the VVehicle to deflect ,t am@ ,torsion ...bar Springflor "Springsl ,when @it-eny ,whel fpassqsf; Qv` lahange fin elevation, such nechansn also being oonstrpofed to exegt corresponding eiorts, or forges in, a vertical di recbionzonpnsibe ends of; the vehicle GhaSS-sor body@ zhatgthe kabrwm ride 0n, a more nearly eyenkeelwithouappreci'able pitching y01@ tossing' when iphe Yehgle is driven .over rough/terrain.

:Anotherwobieet .of the invention-1S to.. provide what may be: termed .-a' ,balancdsprng suspen- -sonfor a motor vehicle, hisbeng accomplished by :providing-1o .tudna-l :torsion bar spring means connecting fthnough the medium of opposed fi'on'b and fear-lever, Varm meanswamar of 'front and rearlwheelsjat eachjsdeofthe Vehicle, and

- 3 like reference characters designate corresponding parts in the `several views.

Fig. l is a fragmentary plan view of a motor vehicle, the b'ody or superstructure thereof being omitted for the sake of clearness, illustrating one embodiment of the invention.

Fig. 2 is a longitudinal sectional elevation taken substantially through lines 2 2 of Fig. 1 looking in the direction of the arrows. Y

Fig. 3 is an enlarged section taken substantially through lines 3 3 of Fig. 1 look-ing in the direction of the arrows.

direction of the arrows.

Fig. 5 is an enlarged sectionjtaken substantially through lines 5-5 of Fig. i1 looking in the direction of the arrows.

4 40 and 4I of wish-bone construction connected together at their outer ends by a spindle and king pin mounting 42 of any conventional type. The inner bifurcated ends of each upper arm are journalled in a bracket 40a secured to the top of the chassis frame. The springs for the vehicle vcomprise two clusters of torsion bars, one at each side o f the chassis extendinglongitudinally thereof. Since, as shown in Fig. 1, the torsion bar spring mechanism and associated parts are duplicated at each longitudinal side of the vehicle, a description of one thereof will suffice. At the front of the vehicle a set or cluster of torsion bars 43 is connected to each of the lower swinging' wheel supporting arms 4I.

"1 Thesel bars. are preferably round bars and are Fig. 6 is an enlarged section taken substantially through lines 6-6 of Fig. 1 looking in the directionrof the arrows.l

'7 isf'an enlarged section taken substantially 'through' lines '1-1 of Fig.' 1 looking in the direction of the arrows.

Fig. 8 is an enlarged section taken substantially'through lines 8-8 of Fig. 1V looking in the direction of the arrows.

Fig. 9 is an enlarged section taken substantially, through lines '9-9 of Fig. 1 v looking in the direction of the arrows.

Fig. lOvis a View illustrating principally the wiringdiagram for the load compensator. Fig. '11, is a plan view of the construction shown in Fig. 12. Fig.'12 is an enlarged section taken substanti'ally through lines I2--l2 of Fig. 1, this View illustrating particularly the"l delayed action switch for the `load compensator, thewiring-diagram of which is shown'in Fig. 10. l

Before explaining in detail the present invention-i't is to be understood that the invention is not limited in its application to the v"details of construction and arrangement of parts illustrated iny the accompanying drawings, sincethe inventionis capable vof' other'embodiments and ofbeing practiced or carried out in various ways. Also it is to be understood thatthe phraseology ory terminologyemployed `hereiny is 'for the` purpose of description and not of limitation.

'This Aapplication is a continuation of my applicationser. No. 530,661, filed April 12, 1944',

now abandoned. l

I'he term axle assemblyfpr axlemeansf'as used herein, is intendedto comprehend any of Ythe-i'sual types of wheell supports such asia solid `4l,irespectively. Inthe particularlvehicle. shown in-this embodiment the rear wheels lilnarehconfnected kby a solid axleGU, although it will beunderstood that the rear wheels maybesupported -byiindepen'dent axlev assemblies .such as :those provided for the front-wheels.. :As-moreiclearly shown inFig- 8, each frontwheel V39is supported by. lupper:l and lower short andlongleveriarms formedof spring steel, and as shown in Figs. 3 and 6the front'terminal ends 43a thereof are squared to fit snugly into a square hole or socket 44 in a bracket 45 rigidly secured as by riveting to the inner end of each wheel supporting arm 4I.l The Socket 44' and 'hence' 'the central longitudinal axis of thefcluster of torsion bars 43 extends inline with the axis of swinging 46 of the wheel supporting arm 4I, each of these arms being pivoted,as .shown in Figs. 3 and 8, to the bottom of the front cross-frame member 41 which is rigidly secured at its ends to the longitudinal chassis or Vsill frame members 48. From this construction it will be readily seen Athat swinging motionof the arms 4|` about their axes 46 will produce swinging orangular motion of the brackets 45 and, hence, will produce a torsional or twisting action on the front ends of the torsion bars 43. Thus, vertical movements of the front wheels 39 will be resistedbyl the torsional resistance of the spring torsiony bars 43.

The chassis side sillsy 43v arerigidly connected together'intermediate the front and ,rear wheels byacross-frame member 4,9. ASecured to Ythebottorn of this frame member .at each side Vthereof is a bracket-50 having a hole or socket 5| through Whichgthree of the to'rsionbars of each 'set' 43 pass to the rear end of the Vehicle. Each bracket 50, therefore, providesa guide for three of the torsion bars which extendpontinuously from the front to the rear of the vehicle. The forth' torsion bar 43b of -each set or cluster, which is connected'in the socket 44'of thebracket 45, terminates at the crossframe member 49, and as illustrated Figs. 1,-4 and?l this fourth torsion'bar 43b has an angularly bent `crank extension 43e .whichis anchored. -in a socket 52v of a bracket riveted'to the front face of theframe member .49. VThe threetorsion bars 43of each set or cluster, which vpass.through the-socket 5| and/ continue fromgthecross-frame member 49 to the .rear of the vehicle, are Asupplemented for the purposeof springing the `rear wheels and providing means for compensating forvarying loadsby anfaddi.- tionaltorsion bar 53 at leach side ofthe Vehicle. The two spring torsion bars 53 function, as heffeinafter described. as load compensating bars and they terminate somewhat in advance off-the cross-frame member 49,2as illustrated in'Figs'. f1 audit-f Y f lpensating torsionbar 53 of eachzset or cluster are squaredand t=snuglyinto a square socket in a socket member55 secured to the outer end .o fga swinging lever 54. The outer end of this leverpis carried in fixed positionl by a hangei` ,bracket 5,6.;.Seured Yt0 One'pf the frame members litfiba-,leverbeins journalled in 'the bracket ss toit rnsaboutlanlaxis coincident with thementral g udinalfaxis v`of 'thenclusterof 'four vbrs'uii and-153;. 'The'linner en'd o'f eachfswinginglever Mlisfpnnectedlbyf Viahvertic'ally extending bolt'l toene of/a lp'airo'ff'torque arms or radiuslbars. Eahblt--SJ extends ,throughapertures54a `and Saa-i 1 the ymembers 54 andi53. :The'connection be' en theb'olt .51, :the 4lever '.54 and `torque .arm i'includesiresilient rubber. :grommets or pads 59 'which permit limited .relativemovement of` theeparts-lduring swingingtmotion `ofsthe lever andftorqueiarm. l Eachf'torque arm or vradiusfhar 58 iis'connected in: thensualzmannerxto therear aide 60 i-which .carriesthefrear wheels-.61e .The forwardlends of ltheitorquearrns vare; pivotally cnnectedsatgGZ to twomembers 63'1of :thereinfrcirgXff-rame of the l'vehicle .whichin .turn are? connected `in`v k'conventional(manner ito. the

sidefsillsl. l r v ,l

From the foregoing-constructionit willfbe seen that vertical movement 'of either v rear wheel 'El vvillbe transmitted through. the faxle 6c/to .one orztheiother of thetorque arms 5,8 which swing a-boutthe pivots 6 2. Vertical swinging; motion offe'lther torque arm will swing onegortheother thus-described that the three torsion -bars f4.3 of

each set-or clusterconnect one front .Wheel with one rear ',wheel at one side of 'the j, vehicle, as a result. ofv Which a twist forftorsion'al deflection impartedat'one end "of thesebars'will be,tr'arigsev 'mittedto 'the oppositeenspandtms torsion-a1 de;

`ectin will `'re'sultin the bars exerting forcesin' corresponding vertical .directionsonuthe frame atpposite ends thereof. "i, j j j It `vvill`be noted that 'eachjlongitudinal torsion barspring means '43 connects a -front wheel and ae'ar vwheel at the same "side 'oit the vvehi'otzle and that 'the jfront "lever arm 4 I extends Y' outwardly Mfrom its v'connection' to the torsion-'bar spring means lwhereas the `rea-r lever larm 54 extendsin'- 'wardly yfrom its connection toffther torsion bar spring` means. kInasmuch as -the leverfarms 544 andi! for the front and rear wheelsrespectively extend from the `frontl 'and rearbf. the vtorsion bai' springmeans 113i inv opposed orfopposite directions. vitvvill vbe seen that said lever arms Will be effective t'o torsionally deect-opposite ends of 'the torsion barvspring vmeans in opposite directions in .response to .vertica'l. motion of vthe .front 'and reark wheels vin corresponding directions. Thus,"thextorsion bar spring means 4will -be effec?1 Ative.through-therlever arms for the front and -rearwheelsto transmit lvertical forces in correspondingdi-rectionssto the( front and rear of the frame in response to'verticalumotion off-either .Wheel.

It will also be, noted that vythetorsion bar springmeans 43..for the pairs yof front andrear .wheelsdiverge-outwardly toward therear of the vehicle Yso l.that the .connection between eachV rear .lever arm Bland its associated torsion'bafrfspring .means is spaced outwardly from thellongjitudinal .center une 'of the vehicle' a. greater'eistane than the'l'spacing ,outwardly (from said center line of the connectionfbetweengthe front lever arm "4l .atlthe Ysame side of the )vehicleand its 4lassocia'ted spring means. Thisv 'construction hasft'he *advantage ir improving fniatenanygthe stabnity lor 'the vehicle as 'well -as 1 increasing the resistance f' he: spring "mechanism to. body roll, f' especially .when thje 4vvehicle 'travels-*on'curves 'i-n -the ."Asillustrated particularly in Figs. financi :"7., they forward end -lof each :compensating v.torsion bar 53isqguidedfor turningxmovement La socket or bracket Sdsecured to .the frame. The zendogf. each' barizfrhas a downward crankfextjension aterriinatng 1in a .return 'bent end portion c5312 mounted Within La coupling icollarxli fon the threaded end member :5.6 iof a turnbuckleashaft 51,., `IYhezends' of this shaft are .tappedto receive the ...threaded y.end members'Ilfwxvhichxmay :'be shifted endwise relative to the shaft -upon rotaztion of .the latter. Secured to .thexshaft-S'I isla wlorm 'gear 58 'meshing :with a :pinionxtrion the Yarmature shaft of :an electric .motor :1:0 suitably carried 'by ther liframe of lthe-vel1icle 'for limited vertical. movement tov compensate :for vthe :arcs through which the ends of the crank arms :53a move when-adjusted by operation of theiturnbuckle. .The motor is of. the reversible :type adapted t be operated to shift v the turnbuckle end members Y166 outwardly'andi-inwardly, such movement. :imparting corresponding swinging motion to the crank'v'extensions 530,03? the compensating "torsion: bars y53 resulting :in increasing er decreasing the j'torsional deflection oritwiSt thereof which in turn-is transmittedto the lever arms v.ifl, thereby causing a change in loadsresistanceat the rear end -of thejvehicle l o f .r.tl-1e spring L vsuspension vto. compensate 'for'..-1load changes. f l Y p As --illustrated ingFigs. 10 to=1-2 inclusive, inroyvision lis made for operating :the :load compensatring motor :'Hlnin one direction or the other-fin order gto increase or decrease the total load .ree sistance of the spring suspension Aat the. rea-r; of the vehiclegso as to `compensate for increases :or decreasesfin .theipay load, such means being-con-A str ucted, "however, Vsoy-,as not to be influenced by mere temporaryV changes or fby vertical :motion ofthe rea-r wheels .and the .rear :axle 60 during travel of the `vehicle. The load compensating mechanism-1will only operate after a prede;- termined delay or interval of time, -as it -is ,only desirable :that this roccur when `the pay loadcf the vehicle is jincreasedor decreased oversa grelatively 4long v period of time.v Y* Q Ing'Figs. .l0 to A1.? Tinclusive there is.-illustrated a .delayed action `sw-itch and wiring diagram-.for operating fthe-motori() Yafter a change in .average height ofthe chassis and body has continued `for agivenperiod of time. This switchLmechanism includes a .dash pot4v 1I containing abodyol' liquid,

such as oil T2, within which an expansible and collapsible bellows `'I3 is immersed. The bottom of the bellows `is electrically connected tofafcontact`14 .which .is suitably grounded. y Attached to thetopof .the bellows isaplungerl15 extending; freely through anpaperture in a shield '[6 secured `Within the upper end of theY dash"`poft .above the level of liquid. Theplun'g'er or' rA carries a'contact disk 7 1 Vfand the 'top vof the potis closed by means 'of 'a cover I8 of non` y d'uctingor insulating material. A"I'he'da'sh -p tis bolted orfastened at 19 to the 'lowerin'tnrned vend 'of abracket 80 rigidly vsecured"by,mean'sioi a ilangeza'toa'portionI of the body o-rframe of'ithe vehicle. As illustrated in`Fig. 10, an v'ad-- ditional supporting bracket 86h secured 'to the `Also vfree to turn acovgcu a.r projecting crank arm 94, this bushing extending beyond.. the end ofthe shaft. 'I'.o the. end ofxthe bushing is anchored one end 83a of .a spiralspringB.V TheV 'other end 83h is bent to extend. over. the end84a lof an operating lever lllrigidly secured ytoV the shaft 82. .The bent end 83h ofthe spring is also extended to engage the upper'edge. of the crank arm 85,the outer end of which is pivotally connected at 86 to the upper: end ofthe plunger 15. The crank arm 94 hasV a .projection 94a underlying and. in normal engagement with the lever 84 andA crank armI 85- The rear end of the voperating lever 84 is pivotally `connected at 81 tothe upper end of a rod.' ori bar 88, the lower end of which is pivotally connected at 89 to a bracket secured to the rear axle 60.

.Fastened to the underside of the dash pot cover 18are a pair of vertically spaced contact membersA 90 and 9|. These members overlap-and underliel the contact disk 11 and are normally spaced a predetermined distance therefrom, as shownV in Fig. l2.. The contact members 90 and 9|ar'e' connected by means of rivetspassing through the cover 18 to a pair of electrical conductors 92 and 93. The Sylphon or bellows 13 is-provided with a bleed orice 13a of predetermined restricted size to delay or slow down, asdesired, the ilow of liquid into and out of the bellows when the latter is expanded or collapsed by the vertical movement in one direction or the other of the plunger 15.V It will be seen that pivotal motion of the operating lever 84 in either direction will be transmitted to the lever 815 through the medium of the spring 83, the'downwardeffort of the lever being exerted by the springend 83h and the upward eiort by the projection 94a. Vertical movement of the plunger15-consequent to swinging motion of the lever 85 will be resisted by the restricted now of liquid through orifice 13a into or out of the bellows. Thus, ordinary short interval changesv inv the relativepositions of the rear axle 80 and'vehicle bodyv or chassis will be resisted sufficiently by the bellows so that merely a deflection Vof the spring 83 will result and the contact disk 11 will'- not move vertically a su'icient distance to make contact to engage either the contact 90 or the contact 9|. Any desired delay in starting the compensatingv motor can be obtained by varying the size of orifice 13a and the distance of the contact disk 11 from thev contacts 90 and 9|. l a ,The construction and operation are, therefore, such that a change in load and the consequent changein the relative vertical positions ofgthe axlefand chassis must, in order to result in a contact being made between disk 11.and contact 9D or 9|, y,continue for a long enough'period of time 'to enable a predetermined quantity of 'liquid to be forced through the' orifice 13a permitting contraction or expansion of the bellows a lsuiiicient amount to enable lthe plunger 15 to travel adistance causing the gap between the contact disk and contact to be closed.

yThe wiring diagramillustrated in Fig. l will be readily understood 4and, briefly, comprises electric conductors and circuit means by which the motor may be operated in either'direction to operate the turnbuckle shaft 61. The conductors 92 and 93 are wired to a pair of solenoids 95 and 95a, the solenoid 95 controlling operation of the motor to exert an elevatinga'ction on the chassis and solenoid 95a controllingthe motor to lower the chassis. Thermotor fis `controlled the upper or lower limits of its vertical adjustf ment for load compensation. These' limit switches are operated to break the circuitsll()V the motor and stop the motor at the points 0f maxi.- mum and minimum compensation for-,load when the car is over or under-loaded. At |08 and 18| are indicated tell-tale. signal lights which may be' positioned on the instrument panel of-,the vehicle to signal the driver when the compensa: tor mechanism is operating. The lamp 10U-is actuated when the solenoid is in circuit and energized, and the lamp IOI is actuated when the solenoid 95a is energized.

In the embodiment herein illustrated the load compensating mechanism operates throughv separate torsion bars 53 to increase or decrease Athe spring resistance at vthe rear of the vehicle so as to compensate for varying loads and maintain the rear end of the vehicle at a substantially constant average riding height. In this embodiment when the vehicle is empty or without pay load, the load compensating torsion bars will preferably be initially placed under torsion or twisted an amount equal to the initial torsional twist given to each of thebars 43 but in the opposite direction. Thus, under initial or normal no-load conditions each compensating bar 53 balances out or offsets one of the bars 43 at ea-ch side of the vehicle, since they are preferably torsionally twisted equally in opposite directions, and hence the rear end of the vehicle is supported when empty at a given average o-r normal riding height by means of -two of the torsion bars 43 at each side-of the vehicle. When the vehicle is under approximately half load the compensating torsion bars 53 will have been untwisted to a point where'they are substantiallyfree of torsional deflection and at this time the rear end of the vehicle will be sprung by means of the six torsion bars 43. Under full load condition the torsion bars 53 will have been twisted or torsionally deilected in the same direction as the bars 43 and to anv equal amount so that at this time the vrear end ofV the vehicle will be sprung by-means of eight torsion bars. From the foregoing it will be observed that the dvehicle spring suspension may readily accommodate a pay load equal tothe sprung weight of the `vehicle while maintaining substantially a constant average riding height landa full normal axle to frame clearance under no-load and full load conditions. Y

Due to the load arms or levers 54 having constant lengths in the illustrated embodiment, a constant spring rate will be provided with, however, a variable ride frequency. In this embodiment, as in the case of' the other embodiments. extremely soft springs may be utilized, since under no conditions is it necessary to utilize springs which are heavier than necessary to carry the sprung loads regardless of whether the vehicle is empty or fully loaded. Forvexample, the

,eiective average spring rate, utilizing the spring suspension of the present invention, can be as low as approximately thirty pounds per inch per wheel as compared with conventional spring suspensions, utilizingeither leaf or coil springs or the combination thereof. necessitating spring rates as'hig-h as onehundred and tenpounds per vinch per wheel. 1 n

In the illustrated embodimentit'will be noted n that additional spring torsion vbars Y'4312 areV proconditions and thus assuring average normal riding height for the front of the vehicle. Sincevextremely soft spring rates are possible at the front and rear wheels with the present torsion bar suspension, it is desirable to 'install'additional springing at the front wheels in'order'to maintain a normal average riding height of the front end under conditions such vas when the frontend tends to dip after a rapid or severe brake application or when the front end vrtends to raise vor elevate excessively during'rapid acceleration of the vehicle. The elevation stabilizer torsion bars 43h under normal conditions' maybe iniunstressed condition, i. e. free of torsionaldeflection, whereas the remaining torsion bars43 Yof the clusters or Asets would be normally deflected an amount suiicientto support thenvehicle, at the average riding height under rio-load conditions. The stabilizer bars 43h would, therefore, be twisted Lin one directionlor the other to resist elevation or lowering of thel front end, asa result of rapid p -acceleration of the vehicle'or sudden application of the brakes, and tend to maintain'the-des'ired average riding heightat the iront end. lhe Abars 4317, onthe other rhandfrnay b'e initiallyl twisted or cleected in one direction or the other when connected to vbrackets 52 lso y,as toposition the front end atthe desired riding height. The 4bars 43h thus resist elevation,l diving"ordipping of the front end and assist in bringing the front end back to normal riding position.

An important feature of the present invention,

inl connection with one aspect thereof, resides in the `Aprovision of torsion bar spring means; con necting corresponding front andjrear 'wheels through levers which are properlyhselected and mounted so ythat Athe spring'lmeans will be responsive to vertical motion of thewheels thus connected. As a result, vertical.forcesrofapproximately the same magnitude Will be applied to the chassis frame andy body at the frontend rear and in they same direction. Anylnurnber of` torsion bars may be used to ,suit the Vparticular vehicle. The torsionbar spring means or mechanism, whatever number of vtorsion bars is utilized, will preferably be'selected as to size and l.

torsional resiliency so as to support thejsprung weight of the Vehicle with the desired axle assembly to framer clearance. The number of torsion bars in the present embodiment is understood to clo be shown merely for illustrative purposes. It i will be seen that with the use of these bars, 'es y which can be easily and cheaply supported along the frame, a very simple and effective ,spring suspensionl is provided which will afford ka much vsmoother and more comfortable Aride undervarya, ing load conditions. Although thepresent spring suspension may be used without-,the load `compensating mechanism and vice versa, itismuch vpreferred that they be employed -coniointlysince b'y so doing the widest advantages of the. invention are thus ensured.

"load 'carrying frame, lever lmeans connected to each wheel and Valso connected to .thefram'e 'at longitudinally spaced points, torsion bari 'spring lmeans connecting 'said lever means and effective Yto transmit vertical forces in corresponding directions to the frame at 'said points in response yto vertical motion of either Wheel, and longitudinal torsion bar spring 'means connected to one lever `means and independent of the other 'for increasingjthe spring resistance at one end of the frame therebyto compensate for varying load "conditions, said lever. means for the front and rear wheels yextendingtransversely from the torsion bar spring means in opposite directions.

'2. In fa spring suspension for a vehicle having a vframe `and front and rear longitudinally "spaced wheels `at lthe same Vside of the frame, lever arm means connected to each wheel and also connected to the frame at llongitudinally spaced localities, longitudinally torsion bar'spring meansconnecting said lever arm means and effective to transmit vertical Aforces in Yco'rrespond, ing directions to the front and rear of the `frame in response to vertical motion of either Wheel, and torsion barv spring means connected to one Wheel Aandindependent of the other for vincreasing `the spring resistance at one end 'of 'the frame thereby jto lcompensate for varying load conditions, saidlever arm means for they front and rear wheelsy extending transversely frornsaid' longitudinal torsion lbar spring means in opposed directions. v y y 3. Ina spring suspension for 'a `vel'iicl'e having 'a frame vand front and reariongitudinany spaced jup and down movement/thereof, a swinging member responsive to vertical motion ofv said axle means and connecting said axle means and 'said second named lever arm means and effective to swing the latter in response to vertical motion of the rear wheel, longitudinal torsion bar spring means common to vsaid front and rear wheels and connecting said lever arm means, said lever arm means for the front' and rear wheels extending transversely 'from said torsion bar spring means in opposed directions and effective to cause said spring means to transmit vertical forceswin corresponding directions to the front and' reary of .the frame in response to vertical motion of either wheel, the connection between the lever arm means for the rear wheel and said spring means being spaced outwardly from the longitudinal center line of the vehicle agreater distance than the spacing outwardly from said center line' of the connection between 4the lever arm means for the front Wheel and said spring means. Y

4, In a spring suspensionf'or a vehicle'having a frame and front and rear wheels at a side of the frame, torsion bar spring-means common to sa'idvfront and rear wheels for supporting the frame Aon said wheels, .means for transmitting ,the eiort of `saidspring means to opposite ends of' thai/rame so as to displace said ends in corresponding vertical directions inl response to vertical motionof. either a frontwheel or av rear wheel, saidtransmitting means including' swinging lever arm means attached to and extending Y111 transversely from said spring means in opposed directions, spring means connecting one of said wheels to the frarne` and being free of connection to theother wheel, and means connected to said last named springV means and operative independently of said rst named spring means to varythe resistance of said second named spring means. Y

' 5; In a spring suspension for a vehicle having ajframe and front and rear wheels ata side of .the frame, front and rear swinging lever arms pivotally connected to the frame .and connected to saidwheels, torsionbar spring means common tosaid wheelsVV and connected tov said front and rear lever arms at the localities of the pivotal connections thereof to 'the frame and operative by said lever arms to displace opposite ends of the frame in corresponding directions upon vertical motion of a front wheel or a rear Wheel,

said lever arms extending from said pivotal contorsion bar spring means connected to one Wheel adjacent one end of the frame and being independent of the'other wheel and operative to increase the spring resistance at said end of the frame. Y

,6. In a spring suspension for a vehicle having a frame and front and rear wheels at a side of the frame, front and rear swinging lever arms pivotally connected tothe frame and connected to said Wheels, spring means v extending continuously between and connected to said front and rear lever arms at the localities of the pivotal connections thereofe-tovtheframe and operative by said lever arms'to displace opposite ends of the frame in corresponding directions upon vertical motion of a front wheel or a rear wheeL'said lever armsextending from said pivotal connections in opposed directions, andladditional spring means connected to one of said wheels adjacent one end of the frame and being independent of the lever arm for the other wheel andoperative to increase the springvresistance at said end of the frame, the connection between the rear lever arm and said first named spring means being spaced outwardly from the longitudinal center line of the vehicle a greater distance than the spacing outwardly from said center line of the connection between the front lever arm and said rst named spring means.

7. In a spring suspension for a vehicle having a frame and front and rear wheels at a side of 'the frame, spring means common to and interposed directions, torsion bar spring means connected to vone wheeland being independent of the other, and means responsive to changes in static load on the frame for varying the effective resistance of said torsion bar spring means. f

8. In a vehicle having a frame and ltwo longitudinally spaced wheels at a side ,of the frame,

' torsion bar spring means extending longitudinally vof the frame for yieldingly supporting the frame on said wheels, leverarm means connected to said frame and to saidspring means adjacent each of said Wheels and responsive to vertical displacement thereof to deflect said spring means nections in opposed directions, and additional 1,2 and thereby simultaneously impart vertical forces in the same direction to opposite ends of the frame, said lever arm means for said Wheels extending transversely from said spring means in opposed directions, and spring means connected `to one of `said wheels and independentl of the other for increasing the spring resistanceat one end of the frame. i v Y c 9. In a spring suspension for a vehicle having a frame and front and rear longitudinally spaced wheels at a side of theframe, swinging. lever arm means connected to each wheel and also pivotally, connected to the frame at longitudinally spaced points, said lever arm means for the wheels extending in opposed directions from the pivotal connections thereof with the frame, torsion bar spring means connecting said lever armmeans and eiective to transmit vertical forces in corresponding directions to the frame at said points in response to vertical motion of either wheel, longitudinal torsion Vbar spring vmeans connected to one lever arm means and operative independently oi the other for increasing the spring resistance'at one end of the frame thereby tov compensate for Varying load conditions, and meansrfor torsionally deflecting said second Anamed spring means. e

10. In a vehicle having a frame and front and rear wheels at the same side of the frame, a swinging lever arm for a rear wheel pivotally connected to the frame and extending in its length transversely of the frame, axle means connected to said rear wheel, alongitudinal member .connecting said axle means and lever arm forv imparting swinging motion thereto, a transversely extending swinging lever arm for said front wheel pivotally connected to the frame and extending'therefrom oppositely to said rst namedilever arm, a spring suspension extending between and connected to said lever arms and operative in conjunction therewith to simultaneouslyrtransmit vertical forces in correspond- Aing directions at opposite ends of the frame upon independent vertical displacement of either wheel, a torsion bar spring means connecting one lever arm with the frame and being independent of the other lever arm, and means for varying the eiTective resistance of said torsion bar spring means. f

11. In a vehicle having a frame and front and rear Wheels at the same side of the frame, a swinging lever arm connected to the rear wheel and swingable in response to vertical displacement thereof, a swinging lever arm connected to the front wheel and swingable in response to vertical displacement thereof, a spring suspension extending-between and connected to said lever arms atvone side of the frame, said lever arms extending from said spring suspension in opposed directions and operative in conjunction therewith to simultaneously transmit vertical forces in corresponding directions at opposite ends of the frame upon independent vertical displacement of eitherr wheel, additional spring means connected to one Wheel and operative independently of the Yother wheel, and means operative by a change in load on the frame for deflecting said last named spring means, the connection between the lever arm .for the rear wheel and said spring suspension being spaced outwardly from the longitudinal center line of the vehicle a greater distance than the spacing outwardly from said center line of the connection between the lever arm for the front wheel and said spring suspension.

12. In a vehicle having a frame and front and rear wheels at the same side of the frame, a swinging lever arm connected to the rear wheel and swingable in response to vertical displacement thereof, a swinging lever arm connected to the front wheel and swingable in response to vertical displacement thereof. a torsion bar spring suspension extending between and connected to said lever arms at one side of the frame, said lever arms extending from said spring suspen-y sion in opposed directions and operative in conjunction therewith to simultaneously transmit vertical forces in corresponding directions at opposite ends of the frame upon independent vertical displacement of either wheel, additional torsion bar spring means connected to one wheel and operative independently of the other wheel, and power operated means operative independently of said spring suspension to increase or decrease the resistance of said last named spring means in response to changes in load on the frame.

13. In a vehicle having longitudinally spaced wheels and a frame supported thereon, said frame including a rigid swinging member, a torsion bar spring suspension common to and responsive to vertical motion of a longitudinally spaced pair of wheels at the same side of the frame, a torsion bar connecting one wheel and the frame and operative independently of the other wheel, the connection between said torsion bar and said one wheel including a swinging lever arm extending in its length transversely of the frame inwardly from said torsion bar and connected to said swinging member, and means responsive to a change in load on the frame and operative independently of said suspension for varying the effective resistance of said torsion bar.

14. In a spring suspension for a vehicle having front and rear wheels and a load carrying frame, a swinging lever arm pivoted to the frame and connected to a front wheel at one side of the frame, a swinging lever arm pivoted to the frame and connected to a rear wheel at the same side of the frame, said lever arms extending in their lengths transversely of the frame and in opposed direction from the pivotal axes thereof and swinging in response to vertical displacement of said wheels, a plurality of spring torsion bars collectively attached adjacent opposite ends to said lever arms at the pivotal axes thereof and subject to torsional deflection in response to swinging motion of either lever arm, a spring torsion bar connected to one lever arm independently of the other lever arm, and means for varying the effective resistance of said last named torsion bar in response to changes in static load on the frame.

15. In a spring suspension for a vehicle having front and rear wheels and a load carrying frame, torsion bar spring means extending between a front and a rear wheel at the same side of the frame, a swinging lever arm directly attached at one end to said torsion bar spring means adjacent the front of the frame and connected at its opposite end to the front wheel, a swinging lever arm directly attached at one end to said torsion bar spring means adjacent the rear of the frame, means for pivotally connecting each lever arm to the frame at the locality of the attachment thereof to said spring means, means for connecting said second named lever Iarm to the rearwheel, said lever arms extending from said spring means in opposed directions whereby vertical displacement of each wheel will swing one of the lever arms to torsionally deflect the torsion bar spring means and cause forces to be exerted in corresponding vertical directions on the frame at or adjacent the points of pivotal connection of said lever arms to the frame, a torsion bar spring connected to one wheel and free of connection to the other wheel, and means for varying the eifective resistance of said torsion bar spring in response to changes in static load on the frame.

16. In a vehicle as set forth in claim 8, power operated means responsive to changes in elevation of an end of the frame for varying the resistance of said last named spring means.

17. In a spring suspension as set forth in claim 2, power operated means responsive to changes in elevation of an end of the frame for varying the resistance of said second named torsion bar spring means.

18. In a vehicle as set forth in claim 8, an electrically operated motor responsive to changes in elevation of an end of the frame and operatively connected to said last named spring means for torsionally deilecting the same to vary the resistance thereof.

19. In a spring suspension for a vehicle having a frame and a pair of front and rear wheels at each side of the frame, front and rear lever arm means pivotally connected to the frame and connected to the Wheels of each pair, torsional spring means extending longitudinally between and connected to the front and rear lever arm means for each pair of Wheels and operative by said lever arm means to displace opposite ends of the frame in corresponding directions upon vertical motion of a front wheel or a rear wheel of a pair of said wheels, said torsional spring means for the pairs of front and rear wheels diverging outwardly toward the rear of the vehicle and the connection between each rear lever arm means and its associated spring means being spaced outwardly from the longitudinal center line of the vehicle a greater distance than the spacing outwardly from said center line of the connection between the front lever arm means at the same side of the vehicle and its associated spring means, additional spring means connected to a wheel of each of said pairs and being independent of the other wheels, and power actuated means operatively connected to said additional spring means for varying the resistance thereof to vertical displacement of the frame.

WILLIAM D. AILISON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,396,549 Beatty Nov. 8, 1921 2,083,381 Hutchison, Jr. June 8, 1937 2,191,211 Krotz Feb. 20, 1940 FOREIGN PATENTS Number Country Date 182,233 Switzerland Jan. 31, 1936 

